Baltimore Ravens defensive back Asa Jackson says he now has NFL approval to use the medication that caused his second violation of the NFL's policy on performance-enhancing drugs.

The NFL announced on Friday that Jackson, a second-year pro who played sparingly as a rookie, has been suspended for the first eight games of the season. He'll be eligible to return to the roster on Nov. 4.

"I was diagnosed with a condition that can be treated with a medication allowed under the NFL/NFLPA Policy after a player obtains a therapeutic use exemption," Jackson said in a statement issued by his agent early Saturday morning.

"I now have the required approval, but the positive test occurred before it was approved. The Policy is very strict, so I have chosen to be immediately accountable. I sincerely apologize to my teammates, coaches, and Ravens fans. I look forward to working hard in training camp and preseason, training hard during the discipline period and contributing to the team immediately upon my return."

Jackson, 23, appeared in three games as a rookie in 2012 before serving a four-game suspension to end the regular season. He said then he tested positive for the prescription drug Adderall. He returned and played in one playoff game during the Ravens' Super Bowl run.

"My reaction to that is that you've got to follow the rules," coach John Harbaugh said after practice Friday. "If you don't follow the rules, you get suspended. That's a fair rule, there's no place for that, and he's getting what he deserves."

The Ravens drafted Jackson in the fifth round (169th overall) last season out of Cal Poly-San Luis Obispo.